My '03 g35 was running great yesterday. I parked the car overnight, started it this morning and it's not hitting on all 6. The service engine light is flashing. The car starts fine and idles rough as well. I recently, within the last two months, had a new throttle body and plugs installed at the dealer. They said the plug wires were fine. The problem doesn't clear up at higher rpm's. I only run 93 octane fuel as it cleared up a knocking/pinging issue. Any ideas?

 

We dont have plug wires as its a coilover design but it sounds like a coil has gone bad...which is common.Get a obd11 scan done and find out which one it is.

 

No plug wires? Sounds like I need to find another mechanic, huh? Again, thanks. It finally stopped raining so I went out to the car, cranked the gas cap a couple of clicks and guess what- I'm embarassed to say that it corrected it. I hate to blame my wife but it's her car- at least until there's a problem with it. All good things, Edward

 

lol lol nice, make sure you borrow a code reader from the auto parts store and clear the codes if you don't own one, if the codes are left in there the ecu will run in a sort of limp mode and its no bueno for performance

 

Funny you should say that- my wife started it this morning and it idled rough, service light flashed... She took off and it ran rough until it warmed up. Now it runs great but the light is on steady. Does that sound like it could still be the result of the gas cap being lose yesterday?

 

go to Checker/Oreilly or Autozone....have them scan the codes and see what it says. Its the only way to offer any real help that isn't just a shot in the dark.

 

Thanks so much. It ran great all day today but the light is still steady. The owners manual said that if it is because of the cap, the light should go off after a few trips. Still gonna take it to the parts store and run codes before it has a chance to go off- thanks again.

 

IT IS highly unlikely that a loose gas cap will make your engine run rough. It will set a DTC if not corrected, but the fuel cap doesn't determine whether your car runs rough one day, and not the other.

If your MIL is blinking/flashing, it means that the condition that your engine is currently experiencing is an ignition malfunction, and that your catalytic converters are on the brink of being damaged...due to the excess amount of fuel not being burned in your cylinder(s), and actually burning down-stream in your exhaust system. Get the car scanned ASAP...you are experiencing an ignition mis-fire, and one or more of your EFI components is causing that to happen.